4,511 research outputs found
Hadronic and electromagnetic probes of hot and dense matter in a Boltzmann+Hydrodynamics model of relativistic nuclear collisions
We present recent results on bulk observables and electromagnetic probes
obtained using a hybrid approach based on the Ultrarelativistic Quantum
Molecular Dynamics transport model with an intermediate hydrodynamic stage for
the description of heavy-ion collisions at AGS, SPS and RHIC energies. After
briefly reviewing the main results for particle multiplicities, elliptic flow,
transverse momentum and rapidity spectra, we focus on photon and dilepton
emission from hot and dense hadronic matter.Comment: To appear in the proceedings of WISH 2010: International Workshop on
Interplay between Soft and Hard interactions in particle production at
ultrarelativistic energies, Catania, Italy, 8-10 September 201
Economic and demographic issues related to deployment of the Satellite Power System (SPS)
Growth in energy consumption stimulated interest in exploitation of renewable sources of electric energy. One technology that was proposed is the Satellite Power System (SPS). Before committing the U.S. to such a large program, the Department of Energy and the National Aeronautics and Space Administration are jointly participating in an SPS Concept Development and Evaluation Program. This white paper on industrial and population relocation is part of the FY 78 preliminary evaluation of related socio-economic issues. Results of four preliminary assessment activities are documented
How Sensitive are Di-Leptons from Rho Mesons to the High Baryon Density Region?
We show that the measurement of di-leptons might provide only a restricted
view into the most dense stages of heavy ion reactions. Thus, possible studies
of meson and baryon properties at high baryon densities, as e.g. done at
GSI-HADES and envisioned for FAIR-CBM, might observe weaker effects than
currently expected in certain approaches. We argue that the strong absorption
of resonances in the high baryon density region of the heavy ion collision
masks information from the early hot and dense phase due to a strong increase
of the total decay width because of collisional broadening. To obtain
additional information, we also compare the currently used approaches to
extract di-leptons from transport simulations - i.e. shining, only vector
mesons from final baryon resonance decays and instant emission of di-leptons
and find a strong sensitivity on the method employed in particular at FAIR and
SPS energies. It is shown explicitly that a restriction to rho meson (and
therefore di-lepton) production only in final state baryon resonance decays
provide a strong bias towards rather low baryon densities. The results
presented are obtained from UrQMD v2.3 calculations using the standard set-up.Comment: 8 pages, 6 figures, expanded versio
The ILW hierarchy
In this paper, we present a new hierarchy which includes the intermediate
long wave (ILW) equation at the lowest order. This hierarchy is thought to be a
novel reduction of the 1st modified KP type hierarchy. The framework of our
investigation is Sato theory.Comment: 8 pages, LaTeX2
Hypomethylating agents in the treatment of acute myeloid leukemia: A guide to optimal use
The hypomethylating agents (HMAs), decitabine and azacitidine, are valuable treatment options in acute myeloid leukemia patients who are not eligible for intensive chemotherapy. Both agents are generally well tolerated, and complications most commonly relate to myelosuppression. Antibiotic / antifungal use, regular monitoring, and proactive patient education are important to minimize these events, and reduce the need for dose delay. Responses to HMAs are often not evident for up to 6 cycles, and there is currently no validated clinical marker for predicting response. Hence, treatment should be continued for at least 4–6 cycles to ensure that patients have sufficient opportunity to respond. Delivery of insufficient numbers of cycles is a key reason for HMA failure, and premature discontinuation must be avoided. Genetic factors offer potential for better predicting responders to HMAs in future, but require further study
Comparison of VLBI, TV and traveling clock techniques for time transfer
A three part experiment was conducted to develop and compare time transfer techniques. The experiment consisted of (1) a very long baseline interferometer (VLBI), (2) a high precision portable clock time transfer system between the two sites, and (3) a television time transfer. A comparison of the VLBI and traveling clock shows each technique can perform satisfactorily at the five nsec level. There was a systematic offset of 59 nsec between the two methods, which we attributed to a difference in epochs between VLBI formatter and station clock. The VLBI method had an internal random error of one nsec at the three sigma level for a two day period. Thus, the Mark II system performed well, and VLBI shows promise of being an accurate method of time transfer. The TV system, which had technical problems during the experiment, transferred time with a random error of about 50 nsec
Integrable lattices and their sublattices II. From the B-quadrilateral lattice to the self-adjoint schemes on the triangular and the honeycomb lattices
An integrable self-adjoint 7-point scheme on the triangular lattice and an
integrable self-adjoint scheme on the honeycomb lattice are studied using the
sublattice approach. The star-triangle relation between these systems is
introduced, and the Darboux transformations for both linear problems from the
Moutard transformation of the B-(Moutard) quadrilateral lattice are obtained. A
geometric interpretation of the Laplace transformations of the self-adjoint
7-point scheme is given and the corresponding novel integrable discrete 3D
system is constructed.Comment: 15 pages, 6 figures; references added, some typos correcte
Observation of Fermi-Pasta-Ulam-Tsingou Recurrence and Its Exact Dynamics
One of the most controversial phenomena in nonlinear dynamics is the reappearance of initial
conditions. Celebrated as the Fermi-Pasta-Ulam-Tsingou problem, the attempt to understand how these
recurrences form during the complex evolution that leads to equilibrium has deeply influenced the entire
development of nonlinear science. The enigma is rendered even more intriguing by the fact that integrable
models predict recurrence as exact solutions, but the difficulties involved in upholding integrability for a
sufficiently long dynamic has not allowed a quantitative experimental validation. In natural processes,
coupling with the environment rapidly leads to thermalization, and finding nonlinear multimodal systems
presenting multiple returns is a long-standing open challenge. Here, we report the observation of more than
three Fermi-Pasta-Ulam-Tsingou recurrences for nonlinear optical spatial waves and demonstrate the
control of the recurrent behavior through the phase and amplitude of the initial field. The recurrence period
and phase shift are found to be in remarkable agreement with the exact recurrent solution of the nonlinear
Schrödinger equation, while the recurrent behavior disappears as integrability is lost. These results identify
the origin of the recurrence in the integrability of the underlying dynamics and allow us to achieve one of
the basic aspirations of nonlinear dynamics: the reconstruction, after several return cycles, of the exact
initial condition of the system, ultimately proving that the complex evolution can be accurately predicted in
experimental conditions
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